DESCRIPTION

These functions are used to access or to change the NIS domain name of the
host system.

setdomainname()
sets the domain name to the value given in the character array
name.
The
len
argument specifies the number of bytes in
name.
(Thus,
name
does not require a terminating null byte.)

getdomainname()
returns the null-terminated domain name in the character array
name,
which has a length of
len
bytes.
If the null-terminated domain name requires more than len bytes,
getdomainname()
returns the first len bytes (glibc) or gives an error (libc).

RETURN VALUE

On success, zero is returned.
On error, -1 is returned, and
errno
is set appropriately.

ERRORS

setdomainname()
can fail with the following errors:

EFAULT

name
pointed outside of user address space.

EINVAL

len
was negative or too large.

EPERM

The caller did not have the
CAP_SYS_ADMIN
capability in the user namespace associated with its UTS namespace (see
namespaces(7)).

getdomainname()
can fail with the following errors:

EINVAL

For
getdomainname()
under libc:
name
is NULL or
name
is longer than
len
bytes.

CONFORMING TO

POSIX does not specify these calls.

NOTES

Since Linux 1.0, the limit on the length of a domain name,
including the terminating null byte, is 64 bytes.
In older kernels, it was 8 bytes.

On most Linux architectures (including x86),
there is no
getdomainname()
system call; instead, glibc implements
getdomainname()
as a library function that returns a copy of the
domainname
field returned from a call to
uname(2).

SEE ALSO

COLOPHON

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